The present invention relates generally to the use of wireless communications and diagnostic systems in automotive vehicles.
The Environmental Protection Agency (EPA) requires vehicle manufacturers to install on-board diagnostics (OBD) for emission control on their light-duty automobiles and trucks beginning with model year 1996. OBD systems (e.g., computer, microcontrollers, and sensors) monitor the vehicle""s emission control systems to detect any malfunction or deterioration that causes emissions to exceed EPA-mandated thresholds. Such a system, for example, is an oxygen sensor located in the vehicle""s exhaust manifold and tailpipe.
The EPA requires that all information monitored or calculated by OBD systems is made available through a standardized, serial 16-cavity connector referred to as the ALDL (Assembly Line Diagnostic Link) or OBD connector. All physical and electrical characteristics of this connector are standard for all vehicles sold in the United States after 1996. The EPA also mandates that, when emission thresholds are exceeded, diagnostic information characterized by OBD systems must be stored in the vehicle""s central computer so that it can be used during diagnosis and repair.
A second generation of OBD systems (xe2x80x9cOBD-IIxe2x80x9d systems) monitors a wide range of data that indicate the performance of the host vehicle. For example, these data can be analyzed to infer the vehicle""s emission performance. In addition to emissions, OBD-II systems monitor vehicle speed, mileage, engine temperature, and intake manifold pressure. OBD-II systems also query manufacturer-specific data, such as data relating to the vehicle""s engine, transmission, brakes, alarm, entertainment systems. OBD-II systems also monitor codes called diagnostic trouble codes, or xe2x80x9cDTCsxe2x80x9d, which indicate a mechanic or electrical problem with the vehicle. DTCs are the codes that typically light a vehicle""s ""service engine soon"" light. In total, OBD-II systems typically access more than 300 segments of data relating to the performance and make of the host vehicle.
In addition to the OBD-II systems, most vehicles manufactured after 1996 have electronic control units (ECUs) that control internal electromechanical actuators. Examples include ECUs that control fuel-injector pulses, spark-plug timing, and anti-lock braking systems. Most ECUs transmit status and diagnostic information over a shared, standardized electronic buss in the vehicle. The buss effectively functions as an on-board computer network with many processors, each of which transmits and receives data. The primary computers in this network are the vehicle""s electronic-control module (ECM) and power-control module (PCM). The ECM typically accesses computers and microcontrollers that monitor or control engine functions (e.g., the cruise-control module, spark controller, exhaust/gas recirculator). The PCM typically controls or monitors ECUs associated with the vehicle""s power train (e.g., its engine, transmission, and braking systems).
When a vehicle is serviced, data from the standardized buss can be queried using external engine-diagnostic equipment (commonly called xe2x80x98scan toolsxe2x80x99) that connect to the above-described 16-cavity electrical connector (called an OBD-II connector for vehicles made after 1996). The OBD-II connector is typically located under the vehicle""s dashboard on the driver""s side. Data transferred through the connector to the scan tool yields data that identify a status of the vehicle and whether or not a specific component of the vehicle has malfunctioned. This makes the service process more efficient and cost-effective.
Some manufacturers include complex electronic systems in their vehicles to access and analyze the above-described data. These systems are not connected through the OBD-II connector, but instead are wired directly to the vehicle""s electronic system. This wiring process typically takes place when the vehicle is manufactured. In some cases these systems transmit data through a wireless network.
It is an object of the present invention to address the limitations of the conventional engine-diagnostic systems discussed above. Specifically, it is an object of the invention to both access and send data over the ODB-II connector using a remote, wireless system that connects to the Internet using an airlink. The device used for accessing and transmitting the data is simple, low-cost, and easy-to-install.
In one aspect, the invention features a method and apparatus for remotely characterizing a vehicle""s performance. The method features the steps of: i) generating data representative of the vehicle""s performance with at least one microcontroller disposed within the vehicle; ii) transferring the data through an OBD, OBD-II or equivalent electrical connector to a data collector/router that includes a microprocessor and an electrically connected wireless transmitter; iii) transmitting a data packet representing the data with the wireless transmitter over an airlink, to a wireless communications system, and then to a host computer; and iv) analyzing the data packet with the host computer. Once analyzed, the data can be used to characterize the vehicle""s performance, e.g. evaluate the vehicle""s electrical and mechanical systems. The data can also be used for other purposes, such as for insurance-related issues, surveys, and vehicle tracking.
The terms xe2x80x98microcontrollerxe2x80x99 and xe2x80x98microprocessorxe2x80x99 refer to standard electronic devices (e.g., programmable, silicon-based devices) that can control and/or process data. For example, a sensor disposed in the vehicle (e.g., an oxygen sensor) would be a microcontroller. xe2x80x9cAirlinkxe2x80x9d refers to a standard wireless connection between a transmitter and a receiver.
In the above-described method, steps i)-iv) can be performed at any time and with any frequency, depending on the diagnoses being performed. For a xe2x80x98real-timexe2x80x99 diagnoses of a vehicle""s engine performance, for example, the steps may be performed at rapid time or mileage intervals (e.g., several times each minute, or every few miles). Alternatively, other diagnoses (e.g. a xe2x80x98smog checkxe2x80x99 that includes inferring the concentrations of hydrocarbons, oxides of nitrogen, or carbon monoxide) may require the steps to be performed only once each year or after a large number of miles are driven. Steps i)-iii) (i.e. the xe2x80x98generatingxe2x80x99, xe2x80x98transferringxe2x80x99, and xe2x80x98transmittingxe2x80x99 steps) may be performed in response to a signal sent from the host computer to the vehicle. Alternatively, the vehicle may be configured to automatically perform these steps at predetermined or random time intervals.
The generating step typically includes generating data encoded in a digital format using the vehicle""s electronic control unit (ECM) and/or power control unit (PCM). The data, for example, describes the vehicle""s mileage, exhaust emissions, engine performance, engine temperature, coolant temperature, intake-manifold pressure, engine-performance tuning parameters, alarm status, accelerometer status, cruise-control status, fuel-injector performance, spark-plug timing, and/or a status of an anti-lock braking system. The data can also be a DTC or related code. The analyzing step features extracting data from the transmitted data packet, and then storing the data in a computer memory or database.
Once stored, the data is processed in a variety of ways. For example, the processing can simply involve determining the vehicle""s odometer reading, and then comparing this reading to a schedule that lists recommended, mileage-dependent service events (e.g., a 5000-mile tune-up). Other algorithms include those that compare current data with data collected at an earlier time to dynamically characterize the performance of the vehicle. In another example, the algorithms compare the data with a predetermined numerical value or collection of values. For example, the data can correspond to a level of the vehicle""s exhaust emissions or mileage; these values can then be compared to predetermined values for the particular vehicle to characterize its performance. More complex processing can include, for example, analyzing the data with a mathematical algorithm to predict the electrical or mechanical performance of the vehicle or a failure of a particular component.
After the processing step, the method can also include the step of sending an electronic text, data, or voice message to a computer, cellular telephone, personal digital assistant or wireless device to alert the end-user of a potential problem. The results from the analysis can also be displayed on similar devices connected to the World-Wide Web or the Internet.
In another embodiment, the method additionally includes the step of sending a second data packet from the host computer system over an airlink to the wireless communications system and then to the vehicle""s data collector/router. In this case, the second data packet is processed by the microprocessor in the data collector/router to generate a signal that is sent to at least one of the vehicle""s microcontrollers. There, the signal is processed and used, for example to adjust a setting in the particular microcontroller. The signal can also be used to update or distribute new software or firmware configurations to one or more of the vehicle""s microcontrollers. In still other embodiments, the signal can be used to make xe2x80x98tailoredxe2x80x99 readings of the vehicle""s diagnostic information, e.g. to perform complex diagnoses (sometimes called xe2x80x98drilling downxe2x80x99) and isolate malfunctioning components in the vehicle""s mechanical or electrical systems.
In another aspect, the invention features a method for sending data to an electrical system in a vehicle. The method features the steps of: i) generating with a host computer a data packet that affects at least one microcontroller disposed within the electrical system of the vehicle; ii) transmitting the data packet from the host computer over an airlink to a wireless communications system and then to a data collector/router (containing a microprocessor and wireless transmitter similar to that described above) disposed in the vehicle; iii) receiving the data packet with the wireless transmitter and sending it to the microprocessor; iv) processing the data packet with the microprocessor to generate data; and v) transmitting the data through an OBD, OBD-II or equivalent electrical connector to the microcontroller disposed within the vehicle""s electrical system.
The invention has many advantages. In particular, wireless transmission of a vehicle""s diagnostic data makes it possible to remotely identify potential problems without bringing the vehicle to a conventional service center. For example, the system can be configured so that when a DTC is generated by a vehicle the code associated with it is automatically sent to the web sites of a service center and the vehicle owner. This way, the service center can diagnose the problem, order to required parts, and schedule the service before the vehicle owner actually brings in the vehicle for service. In certain situations, potential problems with the vehicle can be remotely predicted and addressed before they actually occur. Moreover, data from the vehicle can be queried, stored and analyzed frequently and in real-time (i.e., while the vehicle is actually in use) to provide a relatively comprehensive diagnosis that is not possible in a conventional service center.
The device used to access and transmit the vehicle""s data is small, low-cost, and can be easily installed in nearly every vehicle with an OBD-II connector in a matter of minutes. It can also be easily transferred from one vehicle to another, or easily replaced if it malfunctions.
Communication with the vehicle""s OBD buss can also be bi-directional, making it possible to actually repair certain problems remotely. This, of course, means that in some cases the vehicle""s problem can be both diagnosed and repaired in a completely remote and unobtrusive manner.
Data transmitted from the vehicle can also be analyzed for purposes unrelated to mechanical or electrical problems. For example, the data can be collected and analyzed in real-time to characterize driving patterns (e.g. a vehicle""s speed), automotive part reliability, and emission characteristics. Lessors and renters of vehicles can remotely track mileage for billing purposes. Smog and emission certifications can be easily done in a completely remote manner. Data can also be analyzed to determine the vehicle""s approximate location as a safety or anti-theft measure.
Another advantage of the invention is that data transmitted from a particular vehicle over a wireless airlink can be accessed and analyzed through the Internet without the need for expensive diagnostic equipment. Software used for the analysis can be easily modified and updated, and then used by anyone with access to the Internet. This obviates the need for vehicle service centers to upgrade their diagnostic equipment for next-generation vehicles. The resulting data, of course, have many uses for vehicle owners, surveyors of vehicle performance (e.g., J. D. Power), manufacturers of vehicles and related parts, and vehicle service centers.
Sophisticated analysis of the above-mentioned data yields information that benefits the consumer, vehicle and parts manufacturers, vehicle service centers, and the environment.